The overall goals of this AIDS-CSG are to establish a clinical center for the treatment of HIV infection and related disorders in the OSU Hospitals referral area and to establish a related multidisciplinary basic research effort. Specific objectives include: 1. Establish a cohort of HIV infected patients. 2. Establish a local core of clinical and basic scientists committed to studying this infection. 3. Enter as many of our cohorts as possible into our General Clinical Research Center database - CLINFO. 4. Conduct therapeutic interventions during various stages of HIV infection and follow the course of infection after intervention. 5. Provide adequate resources for the diagnosis and treatment of HIV related conditions such as opportunistic infections and malignancies. 6. Conduct basic science projects to study the epidemiology, pathogenesis, immunology and natural history of HIV infection. 7. Have the cohort available for future studies. Project 1 establishes a cohort of patients, tracks the course of HIV infection, provides the clinical database for other projects, and tests the efficacy and safety of investigational treatments for opportunistic infections. Project 2 tests the potential of alpha-, beta- and gamma-interferons, in combination with AZT, as therapeutic agents. Project 3 tests the hypothesis that vasoactive intestinal peptide (VIP) or other peptides may be responsible for HIV associated diarrhea. Project 5 will assess the effects of HIV infections on Ia expression by human monocytes, the effects of AZT treatment on Ia expression and the ability of monocytes from infected individuals to control growth of MAC. Support services will be supplied by an administrative core, a laboratory core, and a database and analysis core.